Human triggering of a buried weak layer remains possible. The likelihood of warming-related avalanches will increase during the heat of the day.
A weak layer of facets and/or surface hoar is buried around 50 to 100 cm deep. The layer is most prominent on terrain features sheltered from the wind. It remains possible that humans could trigger this layer, where it exists.
Wet loose avalanches are likely in steep terrain during the heat of the day. Cornices are also weakening and could release. These avalanches could step down to deeper layers, forming large avalanches.
A large (size 2) loose wet avalanche triggered a slab about 50 cm deep on Tuesday at 1700 m. It is possible that it triggered the weak layer described in the snowpack summary. Otherwise, the most recent persistent slab activity occurred a week ago. Although the likelihood is decreasing, it remains possible for humans to trigger this buried weak layer. Also expect for sun-exposed slopes to deteriorate over the day, possibly triggering wet avalanches and releasing cornices.
Dry, settled snow is found on shaded aspects in the alpine. A hard melt-freeze crust exists on the snow surface on sun-exposed slopes to the mountain tops and on all aspects below treeline. The crust will transition to wet snow with daytime warming and re-freeze at night.
50 to 100 cm of snow overlies a hard melt-freeze crust from early April. The overlying snow is slow to bond to the crust where pockets of weak surface hoar or faceted grains rest on the crust, which is most likely on northerly aspects at treeline and alpine elevations.
Wednesday Night
Clear skies. 20 km/h southeast ridgetop wind. Treeline temperature -3 °C.
Thursday
Clear skies. 20 km/h east ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 1500 m.
Friday
Clear skies. 20 to 30 km/h east ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 1500 m.
Saturday
Clear skies. 20 to 30 km/h southeast ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 1500 m.
More details can be found in the Mountain Weather Forecast.
